Apparatus for testing the wear resistance of textile yarns



F. BALOGH ET AL APPARATUS FOR TESTING THE WEAR April 16, 1957 RESISTANCE 0F TEXTILE YARNS 5 Sheets-Sheet 1 Filed June 4, 1954 INVENTORS. FERENQ BALOCKH AND y mow RAMASZEDER WHMWM ATTORNEYS 5 Sheets-Sheet 2 F. BALOGH ETAL APPARATUS FOR TESTING THE WEAR RESISTANCE OF TEXTILE YARNS April 16, 1957 Filed June 4, 1954 J 4 N i. m. a a o a m 1m: I r4 I. w {In J W nwle 8 .8 a "a T PU F! A A mi 2 Q t 4 \w mw w ilnmw m z \in n. 353 S. :38

Till k Apnl 16, 1957 F. BALOGH EIAL 2,788,655

APPARATUS F0 ESTI THE WEAR RESISTANCE TEXT YARNS Filed June 4, 1954 5 Sheets-Sheet 3 INVENTORS. FERENC BALOCxH AND BY KAROLY RAM ASZEDER W Mwv ATTORNEYS F. BALOGH ET AL APPARATUS FOR TESTING THE WEAR April 16 1957 2,788,655 A RESISTANCE OF TEXTILE YARNS 5 Sheets-Sheet 4 Filed June 4, 1954 INVENTOR FERE NC Eamon ATTORNEYS Apnl 16,- 1957 F. BALOGH ETAL 2,788,655

APPARATUS FOR TESTING THE WEAR RESISTANCE OF TEXTILE YARNS 5 Shets-$hoet 5 Filed June 4, 1954 INVENVICR FERENC BALOGH WWW ATTORNEYS United States Patent (355cc 2,788,655 Patented Apr. 1%, 195'? APPARATUS FOR TESTING THE WEAR RESISTANCE OF TEXTILE YARNS Ferenc Balogh and Karoly Ramaszeder, Budapest, Hungary, assignors to Licencia Talalmanyokat Ertekesito Vallalat, Budapest, Hungary, a Hungarian enterprise Application June 4, 1954, Serial No. 434,547

7 Claims. (Cl. 73-7) This invention relates to an apparatus for testing the wear resistance of textile yarns.

The knowledge of a possibly reliable value of the wear resistance of textile yarns is, besides those of their tensile strength and elongation, of high importance since in weaving operations the textile yarns are exposed to considerable friction as well. Moreover, in order to decrease the friction of the yarns they are usually sized so as to render them smoother and less liable to wear caused by friction. Obviously, in such cases the knowledge of the wear resistance value of the yarns is still more important, this value then being characteristic also of the applied sizing methods and materials. In practice, however, the quality of sizing has hitherto been determined generally in a subjective manner by means of touching and inspecting, the more objective known methods for determining the wear resistance of sized textile yarns having so far been of laboratory significance and not suitable for practical use.

One of these methods consists in wearing the textile yarn in an apparatus imitating the operation of a loom,

and in counting the number of frictioning contacts. With another method the yarn is being rubbed by means of a rotating metal drum while counting the revolutions of the drum. Still another method consists in tensioning the textile yarn above a slowly rotating friction disk and having a hammer strike thereupon in regular time intervals. The wear resistance is, in this case, estimated by measuring the time till breakage of the yarn. Furthermore, it is known to tension a plurality of warps in a frame and to rub them by means of an iron rod. The quality of the yarns is then estimated by inspection after a certain number of mutual frictioning engagements between the yarns and the iron rod has been performed. In other testing devices the tensioned yarn is being rubbed by means of a polished steel rod lengthwisely or exposed to the wearing action of a prismatic steel body swinging thereabove.

The common drawback of the above stated various known testing methods consists in that the yarns are subjected to the Wearing action of the respective wearing tools but on a portion of their surface, e. g. along a generatrix thereof. Thus, the obtained value of wear resistance cannot be deemed as being characteristic of the be haviour of the yarn under normal manufacturing conditions where it is frictionally engaged generally along the whole of its mantle surface. Another drawback consists in that the value of the specific pressure between the yarn and the wearing tool as well as the area of the friction ing surfaces are uncontrollable so that the test results cannot be compared with one another as would be desirable for obtaining values of practical use.

The present invention aims at eliminating the above said drawbacks and at providing a testing apparatus by which intercomparable wear resistance values may be obtained in an easily practicable manner. The invention is based upon the discovery that reliable values characteristic of the wear resistance can be obtained if the test piece is exposed to the wearing action of a wearing tool along the whole of a predetermined mantle surface thereof and, on the other hand, the wearing conditions are selected so as to yield a well defined frictioning engagement between test piece and wearing tool.

Another object of the invention is to provide means by which a value characteristic of the wear resistance of the yarn to be tested can be obtained in an objective manner, that is without touching or inspecting the yarn after it has been subjected to the wearing action of the testing appliance. It has been found that by selecting the conditions of the wearing test in the manner stated above a value characteristic of the time period of the wearing action till breakage of the yarn under test will also be characteristic of the wear resistance thereof.

Further objects and features of the present invention will be described by taking reference to the aoompanying drawings in which:

Fig. 1 shows--by way of example-the perspective view of an embodiment of the apparatus according to the present invention.

Fig. 2 is a partly sectional View of the said apparatus taken along the lines Il-Il of Figs. 3 and 4.

Fig. 3 represents a cross sectional view taken along the lines III-Ill of Figs. 2 and 4.

Fig. 4 illustrates a plane view, partly in section, taken along the line IV-IV of Fig. 3.

Fig. 5 is a block diagram of the electric equipment of the apparatus.

Fig. 6 shows a detail of Fig. 2 in a side elevational View; finally Fig. 7 represents details of Fig. 2 at an enlarged scale.

Referring to the drawing, the apparatus comprises rotatable first holder means 10 for fixing an end portion of a test piece of yarn to be tested for wear resistance, and rotatable and axially displaceable second holder means 11 coaxially arranged with the first holder means 19 in a distance therefrom for fixing the other end portion of the test piece. The common axis of rotation of the first holder means 10 and the second holder means 11 is referred to by reference numeral 12. The second holder means 11 co-operates with tensioning means adapted to urge the second holder means 11 to increase the distance between the first holder means 10 and the second holder means 11 and thereby to tension the test piece under the action of a constant force along the axis 12 of rotation. To this purpose, the second holder means 11 has an end portion of a cord 13 attached to its outer end portion 14 the other end portion of the cord 13 being fastened to a floating weight 15. A roller 16 guides the cord 13 in such a manner that the weight 15 acting as a tensioning means of constant force urges the second tool holder means 11 to be displaced in the above described manner.

In spaced parallel relationship with respect to the common axis 12 of rotation of the first holder means It and the second holder means 11 there is provided a guide means consisting of a pair of guide rods 17 and it; which are supported by means of their end portions by wall structures 19 and 20 of the apparatus, respectively. The guide means 17 and 18 have support means displaceably arranged therealong, the displaceable support means consisting of a carriage 21 which is adapted to roll along the guide rods 17 and 18 by means of minute rollers 22 and 23, respectively. A tool holder means 24 is supported by the support means 21 and displaceably arranged thereon by means of a pair of guide rods 25 and 26 slidably arranged in guide heads 27 and 2S, respectively, of the support means 21. The tool holder means 24 has an adjusting screw spindle 29 rotatably fixed thereto which is in threaded engagement with a dismountable boss 30 attached to the support means 21. A hand wheel 31 with fluted mantle surface is placed upon a square head portion 32 of the screw spindle 29 and serves for rotating the latter. Obviously, by rotating the hand wheel 31 the tool holder means 21 will be vertically displaced and the common axis 12 of rotation of the first and second holder means and 11, respectively, and the axial centre line 32 of the screw spindle 29 being in intersectional relationship whatever the position of the support means 21 be with respect to the guide means 1.7 and 18 the tool holder means 24 is rendered adjustable in a plane going through the common axis 12 of rotation of the first holder means 10 and the second holder means 11.

The tool holder means 24 has a wearing tool 33 arranged thereon for predetermined wearing engagement with the tensioned test piece held by the first holder means 10 and the second holder means 11 along their common axis 12 of rotation. With the represented embodiment the wearing tool 33 is provided with a wearing edge 34 disposed transversely with respect to the guide means 17 and 18 as is obvious, particularly, from Fig. 4. The wearing tool 33 ismade of a material of great hardness such as e. g. agate, its wearing edge 34 being slightly rounded as illustrated at a larger scale in Fig. 7. It is held inposition by means of a pair of screws 35 and 36 being in threaded engagement with a corresponding pair of brackets 37 and 38 of the tool holder means 24, respectively.

The apparatus is provided with drive means for rotating the first holder means it) and the second holder means 11 with a uniform angular speed and for moving the support means 2i along the guide means 17 and 18 so as to produce a well defined Wearing action along a predetermined surface area of the test piece. In particular, the first holder means Zlt and the second holder means 11 are each provided with a tooth wheel 39 and 4% rotatably supported by the Wall structures 19 and 20, respectively. The first holder means 10 is fixedly attached to the tooth wheel 39 whilst the second holder means Ill and the tooth wheel at! are 'ina per 'se known and therefore not represented key and slot engagement with one another so as to prevent mutual rotation thereof but to permit axial displacement of the second holder means .lll. The tooth wheels 39 and 4d are meshing each with a further tooth wheel 41 and 42 likewisely supported by the wall structures 19 and 2%), respectively. The tooth wheels 41 and 42 have each a ratchet mechanism attached thereto the parts of which are ratchet wheels 43 and d4, ratchet levers 45 and 46, respectively, and pawls supported each by one arm of the ratchet levers 4S and 46, one of the pa'wls being represented in Fig. 3 and referretl to by reference numeral 47.

The ratchet mechanisms are actuated by a swinging axle 48 supported by the well structures 19 and and having a pair of double armed levers 49 and 5t) attached thereto each provided for one of the above described ratchet mechanisms. One arm of the double armed levers 4 9 and St) is by means of extension springs anchored to the wall structures 19 and 20, one of these spring-s being represented in Fig. 3 and referred to by reference numeral 51. The other arm of the double armed levers 49 and 5d are connected by means of link rods 52 and 53 of adjustable length each to one of the other arms of the ratchet levers 45 and 46.

On theopposite 'side of the wall structure 19 the swinging axle 48 has a crank shaft '54 fixed thereto and provided with a cam roll 55 at its end portion. The cam roll '55 cooperates with a cam surface 56 of a control body 57. The latter is fixed to the bottom front surface of a drive disk 53 to be regarded at as the characteristic part of the above said drive means the vertical shaft 59 of which is supported by means of anti-friction radial and thrust bearings 60, 61 and 62, respectively, in a case 63 attached to the base or base plate 64 of the apparatus. The shaft 59 has the worm wheel 65 of a worm gear attached to it the worm of which is referred to by reference numeral 66. The shaft 67 of the Worm 60 is supported by means of anti-friction bearings 67 and 68 in the legs 69 and 70, respectively, of a U-shaped girder '71 attached likewisely to the base plate 64 of the apparatus. One end portion 72 of the worm shaft 67 is by means of a per se known coupling 74 connected to an electric motor 75 of e. g. /4 hp. and 1500 revolutions per minute.

On its front surface opposite to that supporting the control body 57 the drive disk 58 has a connecting rod 76 linked to it which serves for moving the support means 21 along the guide means 17 and 18. The other end portion of the connecting rod 76 is linked to a buckle 78 tightly embracing the boss 39 of the support means 21. The connecting rod 76 is represented with a break therein suggesting that its length is greater than shown in the drawing. it is for sake of enabling to represent the support means 21 with the tool holder means 24 and the wearing tool '33 in an intermediate position with respect to the length of stroke of the support means 21 along the guide means 17 and 18 though, according to the position of the drive disk 58 and of the linkage of the connecting rod 76 on the former, the support means 21 ought to occupy its right hand dead centre position with respect to the drawing.

Furthermore, the apparatus is provided with register means adapted to be operated at least in dependance on the operation of the above described drive means for registering a value characteristic of the Wear resistance to be tested by means of registering at least the number of complete operational cycles of the drive means. With the represented embodiment the number of strokes of the support means 21 is taken as the above mentioned characteristic value. To this purpose, the shaft 59 of the drive-disk 58 is, between the radial anti-friction bearings 6t? and 61, provided with a Worm 78 the Worm gear of which is represented in Fig. 4 and referred to by reference numeral 79. The shaft 80 of the worm gear 79 is extended throughout the length of the apparatus and supported by means of anti-friction radial bearings 31 andSZ in the case 63 as Well as by an anti-friction bearing 83 in the structure wall 20. At its other end the shaft 89 is connected by means of a coupling friction spring 84 to the driving shaft 85 of a revolution counter 86. The counter 86 is adjusted so as to indicate the number of strokes in a window $7 thereof in dependance on the revolution of the drive disk 58.

The revolution counter 36is suitable for registering the above mentioned value characteristic of the wear resistance to be tested since it is obvious that, otherwise similar conditions being taken for granted, the greater the number of revolutions till breakage of the yarn under test, the "greater is the Wear resistance thereof. it means, however, that the indication of the revolution counter 86 has to be read and compared with other numbers which is a method involving additional calculations. If, on the other hand, the test results are indicated diagrammatically first they are readily intercomparable by inspection and secondly they are recorded for permanent availability.

It has been found that such a recording is readily feasible by means of plotting the elongation of the test piece till breakage thereof under the action of the tensioning constant force against the registered value characteristic of the time period of the wearing action. To this purpose, the apparatus is additionally provided with recording means adapted to be operated by the second holder means 11 in dependence on the axial displacement thereof and in dependance on the operation of the drive means 58 for plotting the elongation of the test piece under the action of the tensioning means 14 against a value characteristic of the time period of operation of the drive means 58, i. e. the value registered otherwise by the revolution counter '86. With the represented embodimentthe recording means comprises a per se known regreases corder having a drum 88 for supporting and feeding a tape of diagram paper of the usual type, and writing means 90 for writing engagement with the tape 89 and adapted for transverse displacement thereabove. The feeding drum 88 receives its motion from a worm wheel 91 the worm 92 of which has a common shaft 93 with a further worm wheel 94. The worm associated with the latter is arranged on the shaft 80 and is referred to by reference numeral 95.

The transverse displacement of the writing means 90 is effected by the second holder means 11 by means of an accelerating transmission gear consisting of a pair of pinions 96 and 97 attached to a common shaft and meshing each with a rack indicated by dot-dash lines 98 and 99, respectively. The racks 98 and 99 are attached to the second holder means 11 and the writing means 90 by fastening means 100 and 101, respectively. The diameter of the pinion 96 being smaller than that of the pinion 97, the displacement of the second holder means 11 will obviously be transferred to the writing means 90 in an accelerating manner so that the relatively small elongation of the test piece under the action of the tensioning means 15 will appear on the diagram tape 89 at an enlarged scale.

Referring to Fig. 5, the electric equipment of the apparatus consists of a circuit 102 comprising the electric motor 75 and an actuating switch 103 as well as an automatic circuit breaker 104. Reference numeral 105 refers to the supply net. The circuit breaker 104 is of the usual mercury switch type and is arranged so as to be operable by the descending tensioning means or weight 15 as illustrated in Fig. 6. Its arrangement is selected so as to be reached by the tensioning means 15 only in case of breakage of the test piece. Thus, the circuit breaker 104 forms stop means adapted to be operated by the tensioning means 15 so as to automatically interrupt the operation of the drive means 58 when the second holder means 11 is free to be displaced under the action of the tensioning means 15.

The method for testing the wear resistance of textile yarns to be performed by the above described apparatus comprises the steps of tensioning a test piece of predetermined free length of such yarn by means of action of a constant force represented by the tensioning means 15, pressing the wearing tool 33 against this test piece so as to produce a predetermined angle of rope friction therebetween, moving the wearing tool 33 along a path of predetermined length, i. e. the length of the stroke of the support means 21 so as to produce a well defined wearing action upon the test piece, rotating the latter around its longitudinal axis by means of the holder means and 11 with a uniform angular speed so as to expose a predetermined cylindrical surface area thereof to the wearing action, and registering a value characteristic of the time period of the wearing action till breakage of the test piece.

in operation of the above described apparatus, this method is carried out in the following manner:

The predetermined free length of the test piece, i. e. its length between the holder means 10 and 11 after being inserted therein and without the lengths of its end portions lying between the jaws of the former, is selected so that it be shorter than the maximum distance of the first and second holder means associated with the righthand extreme position of the second holder means 11 with re: spect to the drawing by a distance which sufiices to enable the tensioning means to occupy a floating position till breakage of the test piece. Therefore, the second holder means 11 has to be displaced in a lefthand direction with respect to the drawing against the action of the tensioning means 15 into a position suggested by dotted lines in Fig. 2 so that the test piece be insertable between the jaws of the first and second holder means 10 and 11 in the usual manner. The circuit breaker 104 tilts back and occupies thereby its closing position. Once the test piece is inserted, the tensioning means 15 urges the second holder means 11 to increase the distance 106 between the first holder means 10 and the second holder means 11 and thereby tensions the test piece under the action of a constant force so as to compensate its elongation.

Thereafter the wearing tool 33 is, by means of a suitable scale provided on the top front surface of the hand wheel 31 and an index both known per se and therefor not represented in the drawing, adjusted so as to produce a predetermined angle or of rope friction between the wearing tool 33 and the test piece so that the latter occupies a position illustrated by dot-dash lines and referred to by reference numeral 107 in Fig. 2. For sake of clarity it is stated that by the angle of rope friction the value on in the well known formula S=e,wx is being meant where S is the friction force, e the base number of natural logan'thms and ,u. the friction coefficient between the test piece 107 and the wearing tool 33. As is clear from both illustrations in Fig. 7 representing two different mutual positions of the wearing tool 33 and the test piece 107, during mutual displacement thereof the angle a of rope friction is of constant value its increase with respect to the centre line 108 of the wearing tool 33 on one side thereof compensating its decrease on the other side and vice versa.

The angle a of rope friction has to be selected so as to obtain as little standard deviation of the wear resistance values as possible. In case of e. g. cotton yarns, a value of about 5 has been found suitable. Generally, the value of the angle a of rope friction will not be greater than 10.

The switch 103 is then closed whereby the electric motor 75 is actuated to operate the drive means 58 so that the wearing tool 33 becomes alternately moved along a path of predetermined length defined by the stroke of the support means 21 along the guide means 17 and 13. At the same time, the test piece 107 is intermittently rotated around its longitudinal axis with a uniform angular speed since both the first holder means 10 and the second holder means 11 receive their motion by means of the same swinging axle 48 and like ratchet mechanisms as described above. Thus, rotation of the test piece 107 does not entail either twisting or untwisting of the yarn under test.

The test piece 107 being tensioned under the action of a constant force, i. e. the weight 15, the angle a of rope friction being predetermined and constant, the path of the wearing tool 33 being of predetermined length and the rotation of the test piece 107 around its longitudinal axis going on with a uniform through intermittent angular speed, it is a predetermined surface area of the test piece 107 that is exposed to a well defined wearing action.

In order to register a value characteristic of the time period of this wearing action from the moment of starting the test till breakage of the test piece 107, the revolution counter 86 is, therebefore, adjusted so as to indicate zero number of revolutions, otherwise the number indicated by the same in the moment of starting the test has to be put down so that at breakage of the test piece 107 the actual number of revolutions could be stated. F or plotting the elongation of the test piece 107 under the action of the constant force 15 against the value characteristic of the time period of the wearing action and registered, otherwise, by the revolution counter 86, a tape 89 of diagram paper is being fed from the drum 88 of the recording means and brought into writing engagement with the writing means 90.

As the test is going on, the wearing tool 33 performs alternate movements along the test piece 107. Intermediate positions of the former are indicated by dotted lines in Fig. 2, the corresponding mutual positions of the wearing tool 33 and the test piece 107 being illustrated at a larger scale in the two illustrations of Fig. 7. The test piece 107 becomes thereby elongated so that the second,

holder means 11 will axially be displaced under the action of the weight in a righthand direction with respect .to the drawing. Thus, the Weight 15 is slowly descending toward the circuit breaker 1M. However, the characteristics of the wearing action remain unaltered.

Meanwhile, the revolution counter indicates the increasing number of revolutions of the drive means 58, that is the number of strokes of the wearing tool 33. At the same time, the writing means 9% is being displaced transversely with respect to the tape $9 in dependance on the axial displacement of the second holder means 11 at a relatively higher rate Whilst the feeding drum 83 is being rotated in dependence on the operation of the drive means 58 so that the elongation of the test piece 107 under the action of the tensioning means 15 becomes plotted against a value characteristic of the time period of operation of the drive means 58. Thereby, the tape of diagram paper shows a curve characteristic of both the elongation of the test piece l lii' and the time period of the wearing action thereupon thus yielding a permanent record :of the quality of the yarn readily intercomparable with like records of yarns tested under similar conditions.

At a speed of 120 revolutions per minute of the drive means 53' the breakage of a test piece 187 of e. g. cotton yarns would take place after a time period of about 1 to 1 /2 minutes. At breakage of the test piece 1%7 the second holder means 11 is free to be displaced under the action of the tensioning means or weight 15 which then falls down on the arm of the circuit breaker 104 associated with it thereby automatically interrupting the circuit 102 and the operation of the drive means 58 so as to stop the apparatus.

Thereafter, the circuit 102 of the electric motor '75 is additionally interrupted by the switch 103, the Wearing tool 3 3 is displaced so as to be removed from the level of the common axis 12 of rotation of the holder means 10 and Fill, the remnants of the test piece 1&7 are removed from the jaws of the latter, eventually a fresh test piece iii? of the previous predetermined free length 18 6 is inserted whereby the circuit breaker E64 resumes its closing position. The tape 89 of the diagram paper is readjusted for being suitable to record a further characteristic curve raving the starting point as the curve of the previous recording so as to be readily intcrcomparable therewith and the revolution counter 36 is reset to again indicate zero number of revolutions. Then the wearing tool 33 is readjusted so as to be in frictional engagement with the fresh test piece 167 at the same value of the angle a of rope riction as in the previous test. Thereafter the circuit MP2 of the electric motor '75 is again closed by the switch 193 whereby the above described testing performance is restarted with the fresh test piece llll'.

Obviously, the main significance of the apparatus according to the present invention consists in a well defined wearing action and thus in obtaining readily intercomparable value of the wear resistance of various yarns. Within the scope of the invention, however, various alterations might be effected without departing from the above principle of a well defined wearing action. So, for instance, the wearing tool 33 might be substituted by a rotating disk tangentially arranged with respect to the test piece Hi7. Instead of an alternate motion of the support means 21 a unidirectional motion thereof might be chosen as well. With alternate motion it is also possible to withdraw the wearing tool at every other stroke thereof whereby an intermittent unidirectional motion of the wearing tool 33 is obtained. The rotation of the test piece might be rendered continuous instead of being intermittent.

What we claim is:

1. An apparatus for testing the Wear resistance of textile yarns, comprising a base, a pair of rotatable holder means on said base for clamping a test pieceof such yarn, one of said rotatable holder means being axially displaceable as well, tensioning means on said base adapted to tension said test piece under the action of a constant force,

a Wearing tool for predetermined wearing engagement with said test piece and displaceably arranged therealong on said base, drive means on said base for rotating said holder means at a uniform angular speed and for moving said wearing tool along said test piece so as to expose a predetermined cylindrical surface area thereof to a well defined Wearing action, and register means on said base adapted to be operated at least in dependence on the operation of said drive means for registering the number of complete operational cycles thereof.

2. An apparatus for testing the wear resistance of textile yarns, comprising a base, rotatable first holder means on said base for fixing an end portion of a test piece of such yarn, rotatable and axially displaceable second holder means arranged on said base coaxially with said first holder means at a distance therefrom for fixing the other end portion of said test piece, tensioning means on said base adapted to urge said second holder means to increase said distance between said first holder means and said second holder means and thereby to tension said test piece under the action of a constant force, guide means arranged on said base in spaced parallel relationship with respect to the common axis of rotation of said first holder means and said second holder means, support means displaccably arranged along said guide means, tool holder means supported by said support means and displaceably arranged thereon so as to be adjustable in a plane going through said commonaxis of rotation of said first holder means and said second holder means, a wearing tool arranged on said tool holder means for predetermined wearing engagement with said tcnsioned test piece, drive means .on said base for rotating said first holder means .and said second holder means at a uniform angular speed and for moving said support means along said guide means so as to produce a well defined wearing action around and along a predetermined surface area of said test piece, and register means on said base adapted to be operated at least in dependance on the operation of said drive means for registering the number of complete operational cycles thereof.

3. An apparatus for testing the wear resistance of textile yarn-s, comprising a base, rotatable first holder means on said base for fixing an end portion of a test piece of such yarn, rotatable and axially displaceablc second holder means arranged on said base coaxially with said first holder means at a distance therefrom for fixing the other end portion of said test piece, tensioning means on said base adapts to urge said second holder means to increase said distance between said first holder means and said second holder means and thereby to tension said test piece under the action of a constant force, guide means arranged on said base in spaced parallel relationship with respect to the common axis of rotation of said first holder means and said second holder. means, support means displaceably arranged along said guide means. tool holder means supported by said support means and displaceably arranged thereon so as to be adjustable in a plane going through said common axis of rotation of said first holder means and said second holder means, a wearing tool arranged on said tool holder means for predetermined wearing engagement with said tensioned test piece, said wearing tool being provided with a wean ing edge disposed transversely with respect to said guide means, drive means for rotating said first holder means on said base and said second holder means at a uniform angular speed and for moving said support means along said guide means so as to produce a Well defined wearing action around and along a predetermined surface area of said test piece, and register means on said base adapted to be operated at least in dependence on the operation of said drive means for registering the number of complete operational cycles thereof.

4. An apparatus vfor testing the wear resistance of textile yarns, comprising a base, rotatable first holder means on said base for fixing an end portion of a test piece of such yarn, rotatable and axially displaceable second holder means arranged on said base coaxially with said first holder means at a distance therefrom for fixing the other end portion of said test piece, tensioning means on said base adapted to urge said second holder means to increase said distance between said first holder means and said second holder means and thereby to tension said test piece under the action of a constant force, guide means arranged on said base in spaced parallel relatiouship with respect to the common axis of rotation of said first holder means and said second holder means, support means displaceably arranged along said guide means, tool holder means supported by said support means and displaceably arranged thereon so as to be adjustable in a plane going through said common axis of rotation of said first holder means and said second holder means, a wearing tool arranged on said tool holder means for predetermined wearing engagement with said tensioned test piece, drive means on said base for rotating said first holder means and said second holder means at a uniform angular speed and for alternately moving said support means along said guide means so as to produce a well defined wearing action around and along a predetermined surface area of said test piece, and register means on said base adapted to be operated at least in dependance on the operation of said drive means for registering the number of complete operational cycles thereof.

5. An apparatus for testing the wear resistance of textile yarns, comprising a base, rotatable first holder means on said base for fixing an end portion of a test piece of such yarn, rotatable and axially displaceable second holder means arranged on said base coaxially with said first holder means at a distance therefrom for fixing the other end portion of said test piece, tensioning means on said base adapted to urge said second holder means to increase said distance between said first holder means and said second holder means and thereby to tension said test piece under the action of a constant force, guide means arranged on said base in spaced parallel relationship with respect to the common axis of rotation of said first holder means and said second holder means, support means displaceably arranged along said guide means, tool holder means supported by said support means and displaceably arranged thereon so as to be admeans and displaceably arranged thereon so as to be adjustable in a plane going through said common axis of rotation of said first holder means and said second holder means, a wearing tool arranged on said tool holder means for predetermined wearing engagement with said tensioned test piece, drive means on said base for rotating said first holder means and said second holder means at a uniform angular speed and for moving said support means along said guide means so as to produce a well defined wearing action around and along a predetermined surface area of said test piece, and recording means on said base adapted to be operated by said second holder means in dependance on the axial displacement thereof and in dependance on the operation of said drive means on said base for plotting the elongation of said test piece under the action of said tensioning means against a value characteristic of the time period of operation of said drive means.

6. An apparatus for testing the wear resistance of textile yarns, comprising a base, rotatable first holder means on said base for fixing an end portion of a test piece of such yarn, rotatable and axially displaceable second holder means arranged on said base coaxially with said first holder means at a distance therefrom for fixing the other end portion of said test piece, tensioning means adapted to urge said second holder means to increase said distance between said first holder means and said second holder means and thereby to tension said test piece under the action of a constant force, guide means arranged on said base in spaced parallel relationship with respect to the common axis of rotation of said first holder means and said second holder means, support means displaceably arranged along said guide means, tool holder means supported by said support means and displaceably arranged thereon so as to be adjustable in a plane going through said common axis of rotation of said first holder means and said second holder means, a wearing tool arranged on said tool holder means for predetermined wearing engagement with said tensioned test piece, drive means on said base for rotating said first holder means and said second holder means at a uniform angular speed and for moving said support means along said guide means so as to produce a Well defined wearing action around and along a predetermined surface area of said test piece, register means on said base adapted to be operated at least in dependance on the operation of said drive means for registering the number of complete operational cycles thereof, and stop means on said base adapted to be operated by said tensioning means so as to automatically interrupt the operation of said drive means when said second holder means is free to be displaced under the action of said tensioning means.

7. An apparatus for testing the wear resistance of textile yarns, comprising a base, *a pair of rotatable holder means adapted to tension a test piece of such yarn under the action of a constant force, one of said rotatable holder means being axially displaceable as well, a Wearing tool for predetermined Wearing engagement with said test piece and displaceably arranged therealong on said base, drive means on said base for rotating said holder means at a uniform angular speed and for moving said wearing tool along said test piece so as to expose a predetermined cylindrical surface area thereof, a well defined wearing action, and register means on said base for being operated by and in dependance on the operation of said drive means for registering at least the number of complete operational cycles thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,065,359 Zechmeister Dec. 22, 1936 2,079,591 Bartell May 11, 1937 2,457,276 Ross Dec. 28, 1948 2,537,170 Steiding Jan. 9, 1951 2,591,722 Rounds et al. Apr. 8, 1952 FOREIGN PATENTS 895,287 France Mar. 27, 1944 873,450 Germany Apr. 13, 1953 

